<br/>Microwave measurements are beneficial in obtaining information about the electrical properties of solutions and molecules. A micelle is an aggregate system of amphipathic molecules which form spontaneously at a critical aggregation concentration (CAC). The study of the microwave properties of micelles, which are commonly used in industry and medicine, would provide valuable information about their formation and their behavior in solution. The prior method of microwave measurement at the National Institute of Standards and Technology (NIST) worked well for polar molecules; however, nonpolar molecules which cause the polydimethylsiloxane (PDMS) channels to swell could not be analyzed. To study micelles using the microfluidic high-throughput microwave devices at NIST, a new system was designed to route fluids through the bottom of an aluminum manifold and into channels made of SU-8 photoresist polymer. A manifold was designed using computer-aided drafting and prototypes were 3-D printed. The manifold was machined and implemented to measure capacitance per unit length and permittivity of nonpolar fluids. This method is used to measure both polar and non-polar solutions and provides an improved method to route fluids with less risk to fabricated devices. This new method will enable characterization of synthesized gold nanoparticles, which are dispersed in toluene. This will be investigated as a novel method to determine the CAC of micelles and other aggregate systems. Gold nanoparticles were synthesized from cholorauric acid and functionalized with a thiol and a polymer chain. Mercaptoundecanol (MUD)-capped gold nanoparticles were polymerized with polycaprolactone (PCL) in order to enable the formation of micelles (Au-MUD-PCL). These nanoparticles have been characterized with IR and NMR spectroscopy, and microwave studies could give more information about the size, formation, and dielectric properties of the micelles.

Analytical methods for characterization of synthesized gold nanoparticles in nonpolar solvents

253rd National Meeting (2017)

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